In vitro comparison of cavoatrial (dual stage) cannulae for use during cardiopulmonary bypass

Abstract
An in vitro normothermic, human blood test circuit was constructed to test four cavoatrial (dual stage) cannulae, their right atrial baskets and IVC tips for venous return flow versus siphon drainage gradient. Simulated patient CVP and ECC oxygenator/venous reservoir inlet resistance were held constant at 10 mmHg and 15 mmHg respectively as siphon gradient was varied from 0 centimetres (cm) to -40 cm of blood.